Bentonite-gelled oil waterproofing composition

ABSTRACT

A bentonite composition useful for preventing a flow of water through a structure is disclosed. The composition has substantially all of the bentonite in non-hydrated form by dispersing the bentonite throughout a non-aqueous gel formed from a non-aqueous liquid and a suitable gelling agent for the liquid to form a cohesive mass capable of adhering to a structure while maintaining a desired, cohesive form. The composition can be made into sheets, rods, tubes and the like. For example, the composition can be applied to one side of a water permeable cellulosic fiber containing sheet and the composition side of the sheet secured over an area of potential water flow.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation of Ser. No. 942,935 filed Sept. 18,1978 now U.S. Pat. No. 4,209,568.

FIELD OF THE INVENTION

The present invention relates to an improved, gelled bentonitecomposition having a modeling clay-like consistency while retainingsubstantially all of the bentonite in an unswelled condition forpreventing the seepage of water through structures. In particular, thepresent invention relates to a gelled bentonite composition containing ahigh swelling bentonite clay, an organic liquid, and a gelling agent forthe organic liquid to provide a formable and shapable non-aqueousbentonite clay gel capable of being inserted into a desired location,and shaped as desired to block the potential flow of water through apath of possible seepage while retaining substantially 100% of thebentonite in a non-hydrated or non-gelled form.

PRIOR ART

It is already known to provide seepage resistant structures by employinga mass of swellable bentonite across the path of possible seepage orflow. One such method and composition for impeding the seepage or flowof water is disclosed in U.S. Pat. No. 2,277,286, granted Mar. 24, 1942,to Paul Bechtner, and assigned to the same assignee as the presentinvention. As therein more fully described, commercial bentonite is usedto block leakage or flow of water seepage, and structures of varioustypes are safeguarded against leakage by blocking the path of flow ofthe water with bentonitic or highly colloidal clay which possess thecapacity to swell and gelatinize upon contact with water. One of theclays found best suited for this purpose was the true bentonite obtainedin regions of Wyoming and South Dakota, although other highly colloidal,or bentonitic clays which possess the property of swelling andgelatinizing in water to a substantial degree are also useful. Thesesame clays are also useful in accordance with the present invention.

In accordance with one embodiment of the Bechtner U.S. Pat. No.2,277,286, a stiff putty-like mass is formed by adding to the bentonitefrom 1 to 11/2 times as much water. The resulting putty-like mass,having a portion of its bentonite in a hydrated or swelled condition,forms a mass which is sufficiently cohesive as a result of the partialswelling of the bentonite to adhere to surfaces, so long as the massremains moist, while retaining about 70-80% of its potential absorbantand swelling property. This embodiment disclosed in the Bechtner patenteliminates the construction of expensive and complicated forms, however,20 to 30% of the bentonite clay in the putty-like mass is renderedineffective by the necessary pre-swelling as a result of its initialhydration to achieve a cohesive mass and, further, once wetted, the massmust be maintained moist to achieve the desired cohesiveness. Inaccordance with the present invention, these drawbacks are eliminatedwhile achieving a gelled, bentonite composition having a putty-likeconsistency which maintains its cohesiveness over extended periods oftime while in contact with air without pre-hydrating any of thebentonite contained therein.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a non-aqueous, gelledbentonite composition capable of being adhered to a structure at adesired location in a desired quantity to prevent the seepage of waterthrough the structure.

Another object of the present invention is to provide a non-aqueous,gelled bentonite composition which maintains its cohesiveness withoutexpensive, surrounding forms while maintaining the bentonite insubstantially non-hydrated, non-swelled form.

Another object of the present invention is to provide a non-aqueous,gelled bentonite composition comprising a swellable bentonite clay, anon-aqueous liquid, and a gelling agent capable of providing a cohesivemass when the non-aqueous liquid, gelling agent, and bentonite clay arecombined.

Another object of the present invention is to provide a non-aqueous,gelled bentonite composition having a cohesive, putty-like consistencycapable of being deformed, bent, packed into cavities, and rolled intocoils.

Another object of the present invention is to provide a non-aqueous,gelled bentonite composition wherein the bentonite is substantially 100%non-hydrated by providing a non-aqueous liquid, a gelling agent for saidnon-aqueous liquid, and sufficient non-swelled bentonite admixed withthe gelled liquid to provide a cohesive paste.

Another object of the present invention is to provide a non-aqueous,gelled, substantially non-hydrated bentonite composition capable ofbeing adhered over cracks in concrete foundations to seal the foundationcrack when the bentonite composition is contacted with water.

Another object of the present invention is to provide a non-aqueous,gelled bentonite composition useful for preventing seepage of waterthrough expansion joints in structures, such as cement foundations.

Another object of the present invention is to provide a non-aqueous,gelled bentonite composition capable of being shaped as a sheet, rod,tube, or the like, suitable for a particular use.

These and other objects and advantages of the present invention willbecome readily apparent from the following detailed description of thepresent invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The non-aqueous, gelled bentonite composition of the present inventionincludes a high swelling Wyoming bentonite clay, a non-aqueous liquid,and a gelling agent for the non-aqueous liquid. Sufficient gelling agentis added to the non-aqueous liquid to form a gell. High swellingbentonite clay, preferably in fine powder form is then added to the gelin a suitable quantity to provide a cohesive, paste-like consistencycapable of being formed into a desired shape, without wetting thebentonite. Generally, the non-aqueous liquid will comprise about 40-85%by weight of the liquid-gelling agent combination and the gelling agentis added in an amount in the range of about 15-60% by weight of theliquid-gelling agent combination. The bentonite clay is combined intothe composition preferably by adding the clay to the gelled liquid in anamount sufficient to form a cohesive mass, generally in an amount in therange of 30% to 70% by weight of the total bentonite composition and canbe in the range of 20%-75% by weight. There is no criticality to theorder of addition except for convenience in determining amounts ofgelling agent and bentonite to achieve a particular paste-likeconsistency.

Suitable non-aqueous liquids include any of the organics capable ofgellation by any suitable gelling agent. For example, mineral oil;mineral spirits; naptha; kerosene; microcrystalline wax; linseed oil;aromatic liquids such as xylol; toluol; denatured ethanol;trichlorethylene; solvents such as n-butyl alcohol; methylisobutylketone; n-butyl acetate; toluene, and the like. The more viscousnon-aqueous liquids are preferred so that a lesser amount of gellingagent is required to provide a gel of good cohesiveness such that lessbentonite is required to provide a cohesive mass.

Suitable gelling agents for the above organic liquids include paraffinwax; aluminum stearate; calcium stearate; lithium stearate; sodiumN-octadecylterephthalamate; N-Cocogamma-hydroxybutyramide; any of theoil thickening agents such as the CARBOPOL resins; aluminum octoatetogether with a lower alcohol such as methanol or isopropanol; magnesiumsilicate such as AVIBEST-C containing 37% by weight MgO 43% by weightSiO₂ 4% by weight Fe₂ O₃ hydrated with 12% water at 700° C., ATTAGEL 50having the following chemical composition:

Silicon (SiO₂): 68.0%

Aluminum (Al₂ O₃): 12.0%

Magnesium (MgO): 10.5%

Iron (Fe₂ O₃): 5.0%

Calcium (CaO): 1.7%

Phosphorous (P₂ O₅): 1.0%

Potassium (K₂ O): 1.0%

Titanium (TiO₂): 0.7%

Others: 0.1%

dimethyldioctadecyl ammonium bentonite (BENTONE), or any other gellingagent known to gel and thicken an organic (non-aqueous) liquid.

The cohesive mass of bentonite composition can be used quite effectivelyin concrete construction work. A concrete foundation is generally pouredin segments--the size of a segment depending upon the volume of concretecapable of being poured in one working day. As two segments join theyhave a condition called a "cold joint" in which a hairline crack existsbetween the original concrete and the freshly poured concrete. A waterstop is commonly used to prevent the flow of water through the coldjoint, but water stops have been found to be highly unreliable,sometimes bending as a result of the concrete pressure, leaving a poorseal. The composition of the present invention is adapted to be disposedover such "cold joints" in concrete by pressing the composition againstthe concrete wall to cover the joint between concrete segments. In oneembodiment, a slot or channel can be formed on an outer surface of theconcrete where the two segments join to form a well defined area to befilled with the composition. The slot is not necessary however, sincethe gelled composition described herein will stick to a flat concretesurface.

In another embodiment, the composition of the present invention can beapplied over one major surface of a water permeable support sheet suchas a corrugated paperboard sheet, in a desired size to form anopen-faced panel and the open-faced side of the sheet can be pressedagainst a structure to secure the panel in place to be over a water flowpath.

EXAMPLES EXAMPLE 1

Into warm mineral oil (200° F.) is added 25% by total weight paraffinwax and the oil-wax mixture is stirred vigorously until it forms into agel. Pulverized, high swelling bentonite clay is added to the gel in anamount of 67% by total weight of the gel-bentonite composition to form amastic, or a paste.

EXAMPLE 2

Into warm mineral oil (175° F.) is added 50% by total weight paraffinwax and the oil-wax mixture is stirred vigorously until it forms into agel. Pulverized, high-swelling Wyoming bentonite clay is added to thegel in an amount of 53% by total weight of the gel-bentonite compositionto form a mastic, or a paste. The composition can be maintained warm tomake a less viscous composition or can be cooled to room temperature todevelop structural rigidity.

The gelled compositions of the present invention contain no water, thusnone of the bentonite has been expanded. The composition can be forcedinto cracks on the interior or exterior of a leaking structure whenformed into bars, rods, tubes, and the like. On contact with water, thebentonite begins to expand when potential water leakage contacts thecomposition and seals off further water leakage. The composition of thepresent invention can be used to cover wide areas of leakage such as onsponge type concrete. The composition can be warmed to reduce itsviscosity, poured over a backing material, such as a single facecorrugated board, or a paper board sheet with the open side pressed intoposition.

I claim:
 1. A bentonite composition useful for preventing a flow ofwater through a structure said composition having substantially all ofthe bentonite contained therein in non-hydrated form comprisingbentonite, in an amount of at least 20% by weight of the totalcomposition, dispersed throughout a non-aqueous gel formed from anon-aqueous liquid and a suitable gelling agent for said liquid saidgelling agent included in said composition in an amount sufficient toform a cohesive mass capable of adhering to said structure whilemaintaining a desired, cohesive form.
 2. A bentonite composition asdefined in claim 1 wherein said non-aqueous liquid comprises an organicliquid and wherein said composition comprises a gel containing 40-85%organic liquid, based on the total weight of organic liquid plus gellingagent; 15-60% gelling agent for said organic liquid, based on the totalweight of organic liquid plus gelling agent; and bentonite in an amountsufficient to provide an effective water seal across said structure whensaid bentonite is hydrated.
 3. A bentonite composition as defined inclaim 1 wherein said bentonite and said gelling agent are present in anamount sufficient to form a self cohesive, pasty mass.
 4. A bentonitecomposition as defined in claim 1 wherein said bentonite comprises 20%to 75% by weight of the total composition.
 5. A bentonite composition asdefined in claim 1 wherein said non-aqueous liquid and said gellingagent are added in a weight ratio of 1:4 to 4:1.
 6. A method ofmanufacturing a gelled bentonite composition having substantially all ofthe bentonite contained therein in a non-gelled, unswelled formcomprising:mixing a non-aqueous liquid with a gelling agent capable ofgelling said liquid in an amount sufficient to gel said non-aqueousliquid to form a non-aqueous gel; mixing with said gel bentoniteparticles in an amount of at least 20% by weight of the totalcomposition to form a cohesive mass of bentonite-containing gel.
 7. Amethod as defined in claim 6 wherein said non-aqueous liquid is an oiland wherein said gelling agent is paraffin wax.
 8. A method as definedin claim 7 wherein said paraffin wax is mixed with said oil in an amountin the range of about 25-50% by weight of oil plus paraffin wax.
 9. Amethod as defined in claim 7 wherein said oil is a lubricating oil. 10.A method as defined in claim 7 wherein said oil is mineral oil.
 11. Amethod as defined in claim 6 wherein said bentonite is powdered to asize in the range of 210 to 20 microns.
 12. A method as defined in claim6 wherein said composition is mixed vigorously to form a substantiallyhomogeneous dispersion.
 13. A method of forming a water barrier for aninground foundation comprising,forming a foundation in soil; locating amass of a gelled water sealant composition against said foundation, saidcomposition in the form of a gel comprising bentonite in an amount of atleast 20% by weight of the total water sealant composition; anon-aqueous liquid, and a gelling agent for said non-aqueous liquid inan amount sufficient to form a cohesive, homogeneous dispersion.
 14. Amethod as defined in claim 13 wherein said non-aqueous liquid iscontained in said gelled water sealant composition in an amount of about30-85% by weight of liquid plus gelling agent.